Microray vacuum tube



Dec. 5, 1933. A. G. CLAVIER 1,933,065 I MICRORAY VACUUM TUBE Filed Dec.19. 1931 l4 I I M I I I I L" 17 I3 WI I L' :5

I II 'IIl6 INVENTOR ANDRE c. CLAVIER Patented Dec. 5, 1933 1,938,065MICRORAY VACUUM TUBE Andr G. Clavier, Glen Ridge, N. J., assignor toInternational Communications Laboratories, ,Inc., Newark, N. J., acorporation of New York Application December 19, 1931 I Serial No.582,091

4Claims.

This invention relates to micro-ray vacuum tubes and circuits, andparticularly to a micro-ray vacuum tube with a two-terminal helicoidalreflecting electrode.

The term micro-ray tube or "micro-ray vacuum tube" is to be understoodas meaning a tube for operating with frequencies lying within theapproximate range between 100 centimeters and 1 centimeter.

In my U. s. Letters Patent No. 1,928,408, I have disclosed a method ofand apparatus for producing and detecting micro-rays, that is, rayslying roughly in the range between 100 centimeters and 1 centimeter. Inthe system disclosed in that application there is a micro-ray tubehaving a straight wire filament or cathode, a helical oscillatingelectrode or grid, with its axis along the filament, and a cylindricalreflecting electrode or anode concentric with the oscillating electrode.In a tube constructed in that manner, the dissipation of power in thereflecting electrode is rather high, in a particular'case being about 20watts. Also in that system there is a tendency for oscillations to begenerated in the reflecting electrode, with a lessened eficiency in theoperation of the tube.

The object of this invention is to improve the operating characteristicsof a micro-ray vacuum tube.

A feature of the invention is a reflecting electrode which is helical.

Another feature of the invention is the provision of means for tuningthe reflecting electrode circuit or, alternatively, for preventingoscillations on the reflecting electrode.

In the drawing,

Fig. 1 is a diagrammatic sketch, partly in section, of a micro-ray tubeaccording to this invention; and Fig. 2 is a schematic circuit diagramof a microray tube and associated circuit, and means for tuning thereflecting electrode circuit or, alternatively, for preventingoscillations on the reflecting electrode.

In Fig. 1 a highly evacuated chamber 1" has therein a filament orcathode 2, a helical grid or oscillating electrode 3,"'and a reflectingelectrode 4, in accordance with previous practice. These elements aremounted upon a stem 5 and insulating members 6, '1. Leads 8 and 9 areconnected to the oscillatingtelectrode and leads 10 and 11 are connectedto the reflecting electrode. The reflecting electrode, instead of havinga'solid surface as in previous micro-ray tubes, is a helix. Also thereflecting electrode, instead of having a single lead as in previouspractice, has two leads 10, 11, one connected at eachend of theelectrode and leading from the tube in the opposite direction from theleads '8, 9 from the oscillating electrode. This construction of thereflecting electrode, that is, helical instead of with a solid surface,permits the oscillating electrode to operate at a lower temperature,which increases the emciency of the tube.

In Fig. 2- the tube 1 is shown with elements and leads numberedsimilarly as in Fig. 1. Leads 8 and'9 are connected to aradiating orreceiving doublet\DD1. A lead 12, connected to the center point of thedoublet, is connected to a battery 13 which supplies a positivepotential for the oscillating electrode 3. A battery 14 supplies currentfor the filament 2 and a battery 15 supplies potential to the reflectingelectrode 4 across potentiometer 16, which is provided to permit thiselectrode to be properly biased. Leads 10 and 11 from the ends of thereflecting electrode are parallel to one another and pass through holesin a reflecting screen 17, with suitable insulation between the leadsand the screen. The screen 17 may be made of any suitable reflectingmaterial,

OFFICE such as aluminium, brass or copper, with its refleeting surfacetoward the tube 1. After passing through the screen the leads 10 and 11may be joined and connected to a tap on the potentiometer 16. The screen17 should have a large surface relative to the wavelength at which thesystem is operating, that is, its surface in each direction should betwo or three time's the wavelength- The distance of the screen from thetube may be adjusted so that the circuit of the reflecting electrode istuned or it may be adjusted so that there are no oscillations in thiscircuit. The distance of the screen from the tube for thesev twoadjustments mentioned may be determined in each case by experiment. Ameans is thus provided for controlling the efficiency of the tube,increasing it for transmission purposes, reducingthe tendency toself-oscillations when the tube is used as a detector.

The circuit and reflecting screen 17 may be used with the previous typesof micro-ray tubes, as well as with the improved tube disclosed herein.

What is claimed is:- r

1. A micro-ray tube, a reflecting electrode therein, two leads connectedto said reflecting electrode, a reflector, and apertures in saidreflector through which said leads pass.

2. A micro-ray tube, a reflecting electrode 7' therein, a circuitconnected to opposite ends of oscillating and a reflecting electrodetherein, a 5 radiating doublet, leads connecting the terminals 01 theoscillating electrode, leads connected to the terminals of thereflecting electrode, and means including a reflector, through which thereflecting electrode leads extend, to tune the circuit including thereflecting electrode and its leads to the frequency radiated by thedoublet.

4. The combination according to claim 3 characterized in this that thereflecting electrode is composed of a conductor arranged in a coil'so asto form a cylinder whereby said electrode forms an essential part of theinductance of its tuned circuit.

ANDRE G. CLAVIER.

